So, I've been doing "small" HIITS for about a week now, with a total of about 2 minutes per session.
Today, after getting use to it, I ran for 1 minute with 30-45 second cooldowns, for a little over 10 minutes. My ending heart rate (counted by myself for a minute, might no be too accurate) was 153.
And... WOW is all I can say. I could barely breathe afterwards, and my legs are still hurting. It was fun, but I wouldn't have kept on going if I didn't have music playing. Nothing like a little System of a Down to keep you moving.
Why don't you ask the kids at Tieneman Square?
Body Fat: 12%